Apparatus for automated glucose tolerance testing

ABSTRACT

Devices are provided to automatically access blood from beneath or within skin. These devices include a plurality of injectors configured to drive needles into the skin and draw samples of blood into the device. These devices additionally include a plurality of sensors which can detect a target analyte in the blood samples received by the device. These devices further include a user interface, which may prompt the user to self-administer a dose of a substance, or accept a user input which could affect or otherwise influence the activation of the device (i.e., the firing of needles to draw blood samples into the device and detect an analyte). These devices can be wearable and configured to automatically access blood from skin, for example, to access blood from the skin at one or more points in time after the user has self-administered a dose of a substance.

CROSS-REFERENCE TO RELATED APPLICATION

This application claims priority to U.S. Provisional Patent ApplicationNo. 62/587,294, filed Nov. 16, 2017, which is incorporated herein byreference.

BACKGROUND

Unless otherwise indicated herein, the materials described in thissection are not prior art to the claims in this application and are notadmitted to be prior art by inclusion in this section.

Certain medical states or conditions of a human body can be detected bydetecting one or more properties of blood in the body. In some examples,such medical states can be detected by extracting samples of blood fromthe body and detecting one or more properties of the extracted bloodusing a sensor or other system external to the body. For example, alancet or other skin-penetrating device could be used to penetrate theskin such that blood is emitted from the skin and/or such that blood canbe caused to be emitted from the skin. Blood accessed from a body can beexposed to a sensor (e.g., a sensor placed in contact with blood at thesurface of skin that has been penetrated). Additionally oralternatively, accessed blood can be stored for later analysis. In someexamples, blood may be accessed at two or more points in time to measurea change in a property of the extracted blood over time. In a particularexample, a lancet can be used to penetrate skin at a plurality ofspecified points in time, allowing blood to be emitted from the skinsuch that a blood glucose level of the blood can be measured at a numberof time points using an electrochemical sensor placed in contact withthe emitted blood.

SUMMARY

Some embodiments of the present disclosure provide a system including:(i) a first needle; (ii) a first injector coupled to the first needle;(iii) a first sensor; (iv) a second needle; (v) a second injectorcoupled to the second needle; (vi) a second sensor; (vii) a userinterface; and (viii) a controller, wherein the controller is programmedto perform operations comprising: (a) during a first period of time,operating the user interface to prompt a user to self-administer a doseof a substance; (b) during a second period of time that is subsequent tothe first period of time, operating the first injector to drive thefirst needle into skin to form a puncture in the skin such that a firstamount of blood is received by the first sensor; (c) operating the firstsensor to detect an amount of an analyte in the first amount of blood;(d) during a third period of time that is subsequent to the secondperiod of time, operating the second injector to drive the second needleinto the skin to form a further puncture in the skin such that a secondamount of blood is received by the second sensor; and (e) operating thesecond sensor to detect an amount of the analyte in the second amount ofblood.

Some embodiments of the present disclosure provide a system including:(i) a first needle; (ii) a first injector coupled to the first needle;(iii) a first sensor; (iv) a second needle; (v) a second injectorcoupled to the second needle; (vi) a second sensor; (vii) a userinterface; and (viii) a controller, wherein the controller is programmedto perform operations comprising: (a) during a first period of time,operating the first injector to drive the first needle into skin to forma puncture in the skin such that a first amount of blood is received bythe first sensor; (b) operating the first sensor to detect an amount ofan analyte in the first amount of blood; (c) receiving a user input viathe user interface; (d) responsive to receiving the user input, during asecond period of time that is subsequent to the first period of time,operating the second injector to drive the second needle into the skinto form a further puncture in the skin such that a second amount ofblood is received by the second sensor; and (e) operating the secondsensor to detect an amount of the analyte in the second amount of blood.

Some embodiments of the present disclosure provide a method including:(i) during a first period of time, operating a user interface of adevice to prompt a user to self-administer a dose of a substance; (ii)during a second period of time that is subsequent to the first period oftime, operating a first injector of the device to drive a first needleinto skin to form a puncture in the skin such that a first amount ofblood is received by a first sensor of the device, wherein the firstinjector is coupled to the first needle; (iii) operating the firstsensor to detect an amount of an analyte in the first amount of blood;(iv) during a third period of time that is subsequent to the secondperiod of time, operating a second injector of the device to drive asecond needle into the skin to form a further puncture in the skin suchthat a second amount of blood is received by a second sensor of thedevice, wherein the second injector is coupled to the second needle; and(v) operating the second sensor to detect an amount of the analyte inthe second amount of blood.

Some embodiments of the present disclosure provide a method including:(i) during a first period of time, operating a first injector of adevice to drive a first needle into skin to form a puncture in the skinsuch that a first amount of blood is received by a first sensor of thedevice, wherein the first injector is coupled to the first needle; (ii)operating the first sensor to detect an amount of an analyte in thefirst amount of blood; (iii) receiving a user input via a user interfaceof the device; (iv) responsive to receiving the user input, during asecond period of time that is subsequent to the first period of time,operating a second injector of the device to drive a second needle intothe skin to form a further puncture in the skin such that a secondamount of blood is received by a second sensor of the device, whereinthe second injector is coupled to the second needle; and (v) operatingthe second sensor to detect an amount of the analyte in the secondamount of blood.

These as well as other aspects, advantages, and alternatives, willbecome apparent to those of ordinary skill in the art by reading thefollowing detailed description, with reference where appropriate to theaccompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1A is an exploded view of an example device.

FIG. 1B is a cross-sectional view of the example device of FIG. 1A.

FIG. 2A is a cross-sectional view of an example device mounted to a skinsurface.

FIG. 2B is a cross-sectional view of the example device of FIG. 2A whena needle of the example device is piercing the skin.

FIG. 2C is a cross-sectional view of the example device of FIG. 2B whenthe needle of the example device has retracted from the skin.

FIG. 2D is a cross-sectional view of the example device of FIG. 2C whenblood from the skin has been suctioned to a sensor of the exampledevice.

FIG. 3 is a cross-sectional view of an example device.

FIG. 4A is a perspective top view of an example body-mountable device.

FIG. 4B is a perspective bottom view of the example body-mountabledevice shown in FIG. 4A.

FIG. 5A is a perspective top view of an example body-mountable device.

FIG. 5B is a perspective bottom view of the example body-mountabledevice shown in FIG. 5A.

FIG. 6 is a block diagram of an example system that includes a pluralityof wearable devices in communication with a server.

FIG. 7 is a functional block diagram of an example device.

FIG. 8 is a flowchart of an example method.

FIG. 9 is a flowchart of an example method.

DETAILED DESCRIPTION

In the following detailed description, reference is made to theaccompanying figures, which form a part hereof. In the figures, similarsymbols typically identify similar components, unless context dictatesotherwise. The illustrative embodiments described in the detaileddescription, figures, and claims are not meant to be limiting. Otherembodiments may be utilized, and other changes may be made, withoutdeparting from the scope of the subject matter presented herein. It willbe readily understood that the aspects of the present disclosure, asgenerally described herein, and illustrated in the figures, can bearranged, substituted, combined, separated, and designed in a widevariety of different configurations, all of which are explicitlycontemplated herein.

Further, while embodiments disclosed herein make reference to use on orin conjunction with a living human body, it is contemplated that thedisclosed methods, systems and devices may be used in any environmentwhere the operation of a device to extract a fluid from an environmentof interest by piercing a barrier and/or penetrating an element withinthe environment of interest is desired. The environment may be orinclude any living or non-living body or a portion thereof, a gel, anemulsion, a fluid conduit, a fluid reservoir, etc.

I. OVERVIEW

An oral glucose tolerance test (OGTT) is a medical test that measuresthe body's ability to metabolize glucose. An OGTT may be used to detectdiabetes mellitus, insulin resistance, or other physiologicalconditions. Detection of such conditions may be useful for diagnosingtype 2 diabetes, gestational diabetes, reactive hypoglycemia, or anumber of other conditions. Before conducting an OGTT, a patient mayfast for up to 8-12 hours to reach a baseline (fasting) level of bloodglucose. The fasting glucose level can be measured by taking a bloodsample prior to the beginning of the test. The patient then consumes aglucose solution. After the patient consumes the glucose solution, aseries of blood samples are taken to monitor the patient's blood glucoselevel over time in response to taking the glucose solution. Betweenblood draws, the patient may remain inactive. Typically, an OGTT isconducted by a doctor or nurse, who may take blood samples at regular30-60 minute intervals for up to 3 hours after administration of theglucose solution.

It can be beneficial to provide a device to perform one or more aspectsof the OGTT process, for example, to automatically perform blood drawsfrom a patient and detect glucose therein. By using a device or systemto perform these aspects of the OGTT, a patient may be able to performthe OGTT with minimal supervision, while performing other activities(e.g., while asleep), or outside a traditional clinical setting.Likewise, an automated device or system may perform the OGTT moreaccurately, precisely, or uniformly (e.g., by taking measurements at agreater number of specified time points, by timing the measurements moreaccurately, by performing the blood draws more uniformly, or accordingto some other metric), provide the results more quickly, or perform thetest with reduced pain compared to a traditional OGTT. Other benefitsare also anticipated.

Such a body-mountable, wearable, handheld, desktop, orotherwise-configured device may be configured to access blood within aliving body (or to access some other fluid in some other environment ofinterest) at a number of specified points in time. Such ablood-accessing device could include means for penetrating or piercingthe skin to allow the blood to be emitted from the skin. Suchpenetrating or piercing means could include one or more needles driveninto the skin by an injector that may incorporate chemical propellants,mechanical or electromechanical elements, or some other elements orcomponents configured to drive the one or more needles into the skin andsubsequently to retract the one or more needles from the skin.Subsequently, blood can be emitted from the skin via one or morepunctures or other penetrations in the skin formed by the one or moreneedles.

A body-mountable blood-accessing device could include multiple needles,injectors, seals, suction sources, sensors, blood storage elements, orother components such that the body-mountable blood-accessing devicecould be operated to automatically access blood from a wearer at anumber of specified points in time, e.g., to track the concentration ofan analyte in blood after the user self-administers a dose of asubstance. For example, the blood-accessing device could include atleast two needles, at least two sensors, and at least two injectors,such that the first and second injectors could be operated in successionto measure the amount of an analyte in blood at first and secondspecified points in time.

Blood could be accessed by devices and systems described herein for avariety of applications. One or more properties of accessed blood couldbe measured or detected (e.g., by a sensor of a blood-accessing device,or by some other system that could be exposed to blood accessed and/orstored by such a blood-accessing device). For example, a viscosity ofthe blood, a concentration or state of one or more analytes in the blood(e.g., a level of glucose in the blood, a level of a pharmaceutical, alevel of a metabolite, or some other substance), or some other propertyof the blood could be detected. For example, a concentration of glucose,insulin, one or more hormones, or some other analyte could be detected.Such analytes, and detected concentrations or other properties thereof,could be related to a health state of a person and could be used todetermine such a health state. Further, such determined health statescould be used to determine and/or indicate some medical or other actionto be taken, for example, to take a dose of medicine (e.g., insulin), toperform an exercise, to seek medical attention, or some other action.Additionally or alternatively, detected analyte concentrations or otherproperties of blood accessed at a plurality of points in time couldallow for the determination of one or more physiological baselines orother physiological properties of a person (e.g., a blood glucoseclearance rate, a baseline daily blood glucose profile) and/or thedetermination and/or modification of a medical treatment regimen (e.g.,a timing, dosage, or other property of application of a drug to aperson).

In some examples, a blood-accessing device may include a user interfacethat is configured to provide user-discernible indications (e.g.,visual, audible, and/or tactile indications) of the operation of thedevice to access blood and/or information about accessed blood sensed bysensors of the device, progress or other information related to afunction of the device, or other information. In some examples, the userinterface could additionally provide a means for receiving a user input(e.g., information relating to the timing of one or more futureactivations of the device to access blood from skin, the dosage of aself-administered substance, a user's medical history, a user'sinformation privacy setting, a user's credentials to access a service).In some examples, the device may include a wireless communicationinterface that can transmit/receive data to/from an remote system, forexample, using Bluetooth, ZigBee, WiFi, and/or some other wirelesscommunication protocol. The data transmitted by the wirelesscommunication interface may include data indicative of one or morephysiological parameters or health state measured and/or determinedbased on blood accessed by the device. The wireless communicationsinterface could additionally or alternatively be configured to receivedata from a remote system.

It should be understood that the above embodiments, and otherembodiments described herein, are provided for explanatory purposes, andare not intended to be limiting. Further, the terms ‘access,’‘accessed,’ ‘accessing,’ and any related terms used in relation to theoperation of a device to induce emission of blood from skin are usedherein (unless otherwise specified) to describe any operation orconfiguration of a device or system to receive blood from skin or fromsome other tissue. This could include receiving blood that has beenemitted from skin in response to cutting, piercing, incising, cutting,or otherwise penetrating the skin. This could include actively pulling,wicking, suctioning, or otherwise drawing such emitted blood from theskin and/or form the surface of the skin into the device and/or towardsome sensor, storage element, or other element(s) of the device.Further, while examples and embodiments described herein refer toaccessing blood from skin, it should be understood that methods,devices, and other embodiments described herein could be employed toaccess other fluids from other environments of interest.

II. EXAMPLE OPERATION OF DEVICES TO ACCESS BLOOD

A device could be configured in a variety of ways to access blood fromskin or from some other tissue at a plurality of points in time, e.g.,to facilitate the OGTT. Such a device could include a variety ofpenetrating means (e.g., one or more needles) configured to be driveninto the skin by injecting means (e.g., by a piston and a chemicalpropellant) and subsequently retracted from the skin (e.g., by a spring)such that blood can be emitted from the resultant wound (e.g., puncture)in the skin. Further, such devices could include a variety of means(e.g., suction sources, seals, channels, concave depressions) configuredto draw blood out of the skin, to draw blood emitted from the skin intothe device, and/or to direct such accessed blood toward one or moresensors, blood storage elements, or other elements of the device.Further such devices could include additional elements, sensors,controllers, user interfaces, power sources, communications interfacesor other elements according to an application.

A blood-accessing device or system as described herein could includemultiple sensors, blood-storage elements, needles, injectors, seals,and/or other elements. Each injector could be configured to drive arespective needle into skin and to subsequently retract the needle fromthe skin, in order for a sensor to receive blood emitted from the skin.The blood-accessing device could further include additional componentsconfigured to receive, transmit, measure, modify, or otherwise interactwith blood received from the skin.

A plurality of injectors of a device could be operated to access bloodfrom skin at respective different points in time, e.g., at a number ofpoints in time following self-administration of a dose of a substance,in response to an input received by the user interface, in response to acommand received from a remote system in communication (e.g., wirelesscommunication via Bluetooth, ZigBee, WiFi, or some other wirelesscommunications protocol), in response to a detected command (e.g., abutton press) and/or behavior (e.g., ensuring the user is stationaryusing, e.g., an inertial measurement unit of the device) of a wearer,based on a detected physiological state of the wearer, or according tosome other scheme. In one example, the device could prompt the user viathe user interface to self-administer a dose of a substance (e.g. aglucose solution), and could access blood at one or more points in timerelative to such prompts. Additionally or alternatively, the devicecould receive a user input via the user interface, and could accessblood at one or more time points relative to the received user input.The device could also be operated in response to detecting that thedevice is mounted to the body, detecting that the user is stationary, orin response to some other input.

Such blood-accessing devices could be configured to be used to access,detect, store, or otherwise interact with blood in a variety of ways. Insome examples, such devices could be configured to be mounted to skin orotherwise worn such that the device can access blood automatically,e.g., without intervention from a clinician and/or while the wearerperforms other activities. For example, a controller or other element(s)of the device could operate two or more injectors of the device topierce the skin and access blood at two or more specified points intime.

In some examples, the device could include a mount that secures thedevice to an external body surface (e.g., an area on the wrist).Alternatively, the device could be a handheld device configured to bemanually mounted to a portion of skin and operated to access blood fromthe skin. In some examples, the device could be wall-mounted, situatedon a desktop, or disposed or mounted in some other way, and mounting thedevice to skin could include positioning an arm or other aspect of abody proximate to the device (e.g., positioning skin of the wrist of aperson proximate to a specified aspect of the device). In some examples,one or more elements (e.g., injectors, needles, seals, suction sources,sensors, blood storage elements) could be removable from the device,e.g., such that other elements of the device (e.g., controllers, userinterfaces, mounts) could be reusable by replacing used removableelements of the device.

Blood accessed using devices and methods disclosed herein could be usedfor a variety of applications. Such applications could include anyapplications where one or more properties of a person and/or of blood ofthe person can be detected or determined from two or more volumes ofblood accessed during respective two or more different periods of timeusing such devices. By accessing blood and measuring a physiologicalproperty (e.g., the concentration of an analyte) at a plurality of timepoints, it may be possible to quantify physiological changes over time,monitor the body's reaction to an event, or analyze some other trends.For example, by measuring the level of blood glucose over time followingthe administration of a glucose solution, it may be possible to measurethe body's glucose clearance rate and/or determine whether a patient isdiabetic.

The volume of blood accessed by the device during a particular period oftime can be related to the configuration of the device, and could bebetween approximately one and approximately 10 microliters. For example,the device could be configured to access (e.g., to penetrate the skinand to draw) more than approximately 3 microliters of blood and todetect the concentration of one or more analytes (e.g., glucose,hormones, blood cells) in the accessed blood. The device could beconfigured (e.g., by controlling a stroke length, diameter or shape of aneedle, the shape of a concave depression into which skin could be drawnby suction, an amount of applied suction) to provide a specified minimumamount of blood according to a property of the blood to be measuredand/or a sensor used to detect such a property. For example, the devicecould be configured to access sufficient blood to allow detection of aglucose level of the blood using a low-power electrochemical sensordisposed in the device. In another example, the device could beconfigured to access and store a sufficient amount of blood to allowdetection of a property of the blood by some other device or system thatis provided with the stored blood from the blood-accessing device.

An example of such a blood-accessing device is illustrated in FIGS. 1Aand 1B. The device 100 includes six sections, with each sectionincluding a respective skin-penetrating needle, injector configured todrive the needle into the skin, suction source and sensor, among othercomponents. FIG. 1A shows an expanded perspective view of components ofthe first section of the device (components of other section of thedevice 100 are omitted for illustrative clarity). FIG. 1B is across-sectional view of the device 100 illustrated in detail elements ofthe first section of the device 100. The device 100 includes a housing110 that is formed to include a number of chambers (e.g., 131) andevacuated volumes (e.g., 141) of the sections as well as other features.Blood-accessing device 100 could be used on its own (e.g., by placing abottom surface of the device 100 in contact with skin), could be part ofanother device (e.g., part of a wrist-mountable or otherwisebody-mountable device), could be a removable module of another device,or could be configured or operated in some other way.

The first section includes elements disposed within a first chamber 131formed in the housing 110. The chamber is shown as a cylindrical shapeformed in the housing, but could assume other shapes according to anapplication. The chamber contains a needle 120 configured to penetrateskin, a piston 130 coupled to the needle 120 and configured to slidablymove within the chamber 131 (e.g., along the long axis of the chamber131), and a propellant 135 configured to slidably move the piston 130within the chamber 131 to drive the needle 120 into skin and further todrive the needle 120 through a seal 143 disposed on a bottom surface ofthe housing. The chamber additionally contains a spring 137 configuredto retract the needle 120 from the skin, a sealant layer 139 that isconfigured to be pierced by the needle 120 and a resistive element 136configured to ignite the propellant 135 by providing sufficient heat tothe propellant 135 when current passes through the resistive element136.

The top of the chamber 131 is closed by a circuit board 115 or othermember bonded or otherwise adhered to the housing 110. Electronics 150(e.g., one or more controllers, logic gates, current sources, electronicswitches, radio transceivers, analog-to-digital converters) disposed onthe circuit board 115 could be configured to perform operations of thedevice 100, e.g., to apply current to the resistive element 136 (or toother resistive elements or to operate other components of otherinjectors of the device 100) to ignite the propellant 135 at a specifiedpoint in time, to operate a sensor to detect a property of bloodaccessed from skin by the device 100, or to perform some otheroperations according to an application.

A needle channel 121 is formed in the bottom of the chamber 131 throughthe housing 110 such that the needle 120 can be driven into skinproximate the bottom of the housing 110. A piston vent 133 is formedthrough the piston 130 and chamber vents 132 are formed in the housing110 to allow gases produced by the ignition of the propellant 135 to bevented out of the device such that the spring 137 can retract the needle120 subsequent to the ignited propellant 163 causing the piston 130 todrive the needle 120 through the seal 143 and into skin. The diameter,number, geometry, and other properties of the vents 133, 132 could bespecified to control a force with which the piston 130 drives the needle120, a duration of time during which the needle 120 penetrates skinbefore being retracted by the spring 137, or other properties ofoperation of the device 100.

The seal 143 includes a concave depression 123 through which the needle120 penetrates the seal 143 to form a hole in the seal 143 when drivendownward by the piston 130. A channel 145 is formed above the concavedepression 123 behind the seal 143 and connecting the region behind theseal 143 with an evacuated volume 141 formed in the housing 110. The topof the evacuated volume 141 is sealed by the circuit board 115.Atmospheric gases are prevented from entering the evacuated volume 143through the chamber 131 by the sealant layer 139 and prevented fromentering the evacuated volume 141 through the bottom of the housing 110(e.g., through the concave depression 123) by the seal 143. A sensor 140is contained within the evacuated volume 141. The pressure in theevacuated volume 141 is sufficiently lower than the pressure of theenvironment surrounding the device 100 that, when one or more holes areformed in the seal 143 by the needle 120, the evacuated volume 141 actsas a suction source to draw blood from a formed puncture in the skin,through the one or more holes in the seal 143, through the channel 145,and into contact with the sensor 140 such that the sensor 140 can detectone or more properties of the blood (e.g., a glucose concentration ofthe blood). In such an example, the evacuated volume 141 additionallyacts as a collection chamber for blood. The evacuated volume 141 couldhave a pressure less than approximately 50 kilopascals. Other elementsof the device 100 (e.g., the channel 145, the concave depression 123,the needle channel 121, a hollow channel formed in a hollow needle ofthe device (e.g., in examples where the needle 120 is hollow), or someother elements of the device 100 could act as a collection chamber forblood drawn from skin by a suction source.

The device 100 additionally includes a conformal layer 170 configured toconform to the skin such that suction applied by the evacuated volume141 (or by some other suction source of the device 100) through one ormore holes in the seal 143 is applied to skin proximate the one or moreholes in the seal 143. This could include the conformal layer 170including polyurethane, soft rubber, polymeric gel, or some othercompliant material. Additionally or alternatively, the conformal layer170 could include an adhesive layer, a glue (e.g., cyanoacrylate), atape, or some other adhesive substance.

FIGS. 2A-D illustrate the operation of the device 100 to access bloodfrom skin 105. FIG. 2A shows the device 100 having been mounted to theskin 105; this could include the device 100 being adhered to the skin105 using an adhesive or mount (e.g., a mount configured to encircle awrist of a person such that the device 100 is maintained in contact withskin of the wrist). Alternatively, the device 100 could be a handhelddevice designed to be manually or otherwise maintained in contact withthe skin 105. In another example, the device 100 could be a desktop orother relatively immobile device and a body part comprising the skin 105could be positioned proximate the device 100 as illustrated.

FIG. 2B shows the propellant 135 expanding to slidably move the piston130 downward, compressing the spring 137 and driving the needle 120 topierce the seal 143 and further driving the needle 120 into the skin105. Properties of the spring 137 (e.g., a spring constant, a degree ofinitial loading), piston 130 (e.g., a mass, a coefficient of frictionwith the sides of the chamber 131, a diameter and number of piston vents133), needle 120 (e.g., a diameter, a tip geometry, the presence of afluoropolymer coating or other anti-friction coating), chamber 131(e.g., a geometry, a volume of the region above the piston), propellant135 (e.g., an amount of the propellant, a mix of chemicals comprisingthe propellant), or other elements of the device 100 could be specifiedto maximize the speed with which the needle 120 is driven into the skin105 to, e.g., reduce discomfort induced in a user by operation of thedevice to penetrate the skin 105.

FIG. 2C shows the piston 130 and needle 120 retracted from the skin 105partially due to venting of propellant gases through the piston vent 133and chamber vents 132 (indicated by the arrow) and the force generatedby the spring 137 due to compression of the spring 137 by the movementof the piston 130 downward when driving the needle 120 into the skin 105(shown in FIG. 2B). FIG. 2C additionally shows a hole 144 formed in theseal 143 and a puncture 107 formed in the skin 105 by the piston 130driving the needle 120 through the seal 143 and into the skin 105. Thehole 144 in the seal 143 allows skin proximate the hole 144 (e.g., skinbeneath the concave depression 123) to be exposed to suction from theevacuated volume 141. This causes the skin 105 proximate the hole 144 tobe drawn up into the concave depression 123. Further, the skin 105 isdrawn up into the concave depression 123 such that the puncture 107 isaligned with the hole 144. This could facilitate the drawing of bloodfrom the skin 105 (e.g., from the puncture 107) through the hole 144into the device 100. In examples where skin is drawn, by suction, towarda device such that a formed puncture in the skin is not aligned with oneor more formed holes in a seal, blood could still be drawn into thedevice, e.g., due to wicking, surface tension, the blood filling thespace between the skin and device, or by some other mechanism.Properties of the spring 137, piston 130, needle 120, chamber 131,propellant 135, or other elements of the device 100 could be specifiedto maximize the speed with which the needle 120 is retracted from theskin 105 and/or minimize the duration during which the needle 120pierces the skin 105 to, e.g., reduce discomfort induced in a user byoperation of the device to penetrate the skin 105. Further, elements ofthe device 100 could be configured to minimize an amount of bloodemitted from the skin 105 that is deposited on the surface of the skin105 rather than being drawn and/or suctioned into the device 100 (e.g.,the device 100 could be configured to suction the skin 105 into contactwith the seal 143; the seal 143 could include a hydrophobic or othercoating to repel blood).

FIG. 2D shows blood 109 emitted from the skin 105 (e.g., from thepuncture 107 formed in the skin 105) that has been drawn through thehole 144 and into the device 100. Further, the emitted blood 109 hasbeen directed, via the channel 145, to the sensor 140. This couldinclude suction from the evacuated volume 141 drawing the blood 109through the channel 145 to the sensor 140. Additionally oralternatively, the blood 109 could be directed to and/or through thehole 144, through the channel 145, and/or to the sensor 140 byhydrophobic and/or hydrophilic coatings on one or more surfaces of theseal 143, channel 145, or other elements of the device 100. For example,a path from the hole 144 through the channel 145 to the sensor could becoated with a hydrophilic substance; other surfaces of the device 100that could come into contact with the blood 109 could be coated with ahydrophobic substance. Additionally or alternatively, the channel 145(or other elements of the device 100) could be sized to direct the blood109 using capillary action. The channel 145 or other elements of thedevice 100 could include a coating of heparin or some otherpharmaceutical to reduce coagulation and/or clotting of the blood 109 inthe device (e.g., to increase the duration and/or amount of blood 109flowing into the device 100 and/or to the sensor 140).

The shape, size, geometry, or other properties of the concave depression123 could be specified to maximize an amount of blood emitted from theskin 105 in response to being pierced by the needle 120. For example,the concave depression 123 could have a conical shape. The device 100could additionally or alternatively be configured in other ways tomaximize an amount of blood emitted from the skin 105. For example, thedevice 100 could be configured to increase blood flow in the skin 109proximate the device 100 and/or proximate the concave depression 123 by,e.g., heating the skin 105 before penetration, applying a frictive forceto the skin before penetration (e.g., by rubbing the skin), applyingsuction to the skin 105 before penetration, applying a vasodilating,anti-clotting, anti-coagulant, or other pharmaceutical (e.g., heparin,lidocaine) before, during, and/or after penetration of the skin 105, orby being configured or operated in some other way.

Further, the properties of the needle 120 could be specified to maximizethe amount of blood emitted from the skin 105, minimize discomfortinduced by penetration of the skin, or according to some otherconsideration. For example, the tip of the needle 120 could include atriple-bevel to minimize deflection of the skin 105 and/or to minimizeinduced discomfort due to piercing of the skin 105 by the needle 120.Alternatively, the needle 120 could have a chisel tip (e.g., a singlebevel), could have a flat ‘razor’ blade end, could include a taper(e.g., could become thinner toward the end), could be round, flat, orcould be configured in some other way to, e.g., maximize blood emittedfrom the skin 105. The needle 120 could be serrated. The diameter (orgauge) of the needle 120 could be specified to maximize the amount ofblood emitted from the skin 105 and/or to minimize discomfort induced bypiercing of the skin 105 by the needle 120. For example, the needle 120could have a gauge between approximately 21 gauge and approximately 36gauge.

Further, the distance the needle 120 (or needles) pierces into the skin105 (related, e.g., to properties of the propellant 135, chamber 131,piston 130, spring 137, needle 120, and/or other elements of the device100) could be specified to maximize the amount of blood emitted from theskin 105 and/or to minimize discomfort induced by piercing of the skin105 by the needle 120. For example, the device 100 could be configuredsuch that the needle 120 penetrates skin 105 to a depth of approximately2 millimeters. In some examples, the device 100 could be configured suchthat the needle 120 penetrates skin 105 to a depth that containscapillaries and/or other blood vessels but that does not contain manynerve endings (e.g., to a depth near the transition between theepidermis and dermis layers of the skin 105). Additionally oralternatively, the device 100 could be configured to drive the needle120 into the skin 105 at a different angle than the one depicted (i.e.,an angle other than approximately 90 degrees).

The propellant 135 could include a variety of chemicals and combinationsof chemicals. For example, the propellant 135 could includenitrocellulose, butane, azide, or some other energetic gas-producingsubstance or other chemical(s). In some examples, the propellant couldbe formed and/or modified before use, e.g., the propellant could includeoxygen and hydrogen formed from water by electrolysis. Alternatively,the propellant could include a compressed gas (e.g., CO₂, N₂, aircompressed by a pump or other means, a goas generated by the device 100by electrolysis or some other method or means) to which the piston 130is exposed to drive the needle 120 into the skin 105. Additionally oralternatively, the piston 130 could be driven by a low pressure (e.g., avacuum, a suction source, an evacuated volume) beneath the piston 130.

The use of the resistive element 136 to ignite the propellant 135 isintended as a non-limiting example. Other means for igniting a chemicalpropellant (or some other chemical or element of the device 100according to an application) are anticipated, including but not limitedto generating an electrical spark (e.g., by applying a high voltageacross a spark gap or between electrodes of the device 100),illuminating the propellant (e.g., using a laser, an LED, or some otherlight-emitting element(s)), applying a fore and/or vibration to thepropellant (e.g., using a piezoelectric elements), or changing apressure to which the propellant is exposed. Further, the illustratedconfiguration of the piston 133 and chamber 132 vents are non-limitingexamples; more or fewer vents, vents located at different locations, orvents configured in some other way could be included to facilitate apiston driving a needle into skin and/or subsequently retracting theneedle from the skin. In an example, one or more of the vents could benormally closed and configured to open (either permanently ortemporarily) when a pressure across the vent exceeds some level (e.g.,when the pressure behind the piston 130 increases above a specifiedpressure due to ignition of the propellant 135). Additionally oralternatively, one or more vents could be located in the chamber 131such that gases behind the piston 130 (e.g., high-pressure gasesproduced by ignition of the propellant 135) are able to leave thechamber 131 through the vent only when the piston 130 is displaceddownward in the chamber 131 by some specified distance.

The piston 130, chamber 131, propellant 135, spring 137, and otherelements of the device 100 comprise an injector configured to drive theneedle 120 into skin and subsequently to retract the needle from theskin by igniting a chemical propellant. However, the device 100 couldinclude additional or alternative injectors configured to achievedriving of the needle 120 into skin and subsequent retraction thereof.In some examples, the injector could include one or more pre-loadedsprings configured to be released (e.g., by a manual button, by asolenoid or other electromechanical actuator). The injector couldinclude one or more magnets and/or cams configured to translate a forcebetween the one or more magnets and other elements of the device 100 toproduce driving and/or retracting force(s) that could be applied to theneedle 120. In some examples, the injector could include one or moremotors or other electromechanical actuator configured to apply drivingand/or retracting force(s) directly to the needle (e.g., through arack-and-pinion mechanism, using a cam, by applying magnetic forcesusing a solenoid) and/or by charging up a spring (e.g., a rotary spring)that could apply such force(s) to the needle 120. In some examples, theneedle 120 could be applied against the skin with a constant force thatis less than a force necessary to pierce the skin, and a vibrator (e.g.,a vibrating motor, a piezoelectric or otherwise configured ultrasonictransducer) could vibrate the needle 120 such that the needle 120pierces the skin. Other injectors or other means and methods for drivingthe needle 120 into the skin and subsequently retracting the needle areanticipated.

Suction applied to the seal 143 could be applied by a variety of meansor methods. As illustrated in FIGS. 2A-D, suction can be provided by anevacuated volume 141 that has a pressure that is lower than the pressureof the atmosphere surrounding the device 100. Additionally oralternatively, suction could be provided by a pump, a chemical processthat causes a decrease in pressure (e.g., by causing a decrease intemperature, by consuming nitrogen, oxygen, or some other gas from anenclosed volume (e.g., 141) and/or by changing a phase of such gases), aspring-loaded or otherwise actuated, enclosed volume that can beactuated to increase in size (thus producing suction), or by some othermeans of producing suction. In some examples, blood emitted from skin(e.g., due to penetration of the skin with a needle as described herein)could be drawn into the device 100, applied to a sensor (e.g., 140),stored, or otherwise manipulated according to an application withoutusing a source of suction, e.g., by using hydrophobic and/or hydrophiliccoatings and/or capillary forces to control the location and/or movementof blood within and/or relative to the device 100, by locating a sensor,blood storage element, or other element(s) of the device 100 proximateto the location at which the device 100 pierces the skin with the needle120, or by configuring the device 100 in some other way. In someexamples, e.g., when the needle 120 pierces a vein or other largervasculature, blood pressure or other forces within or beneath skin maycause a sufficient amount of blood to be emitted from the skin.

When suction is provided by a suction source that comprises an evacuatedvolume (e.g., 141), a pressure within the evacuated volume could bespecified to provide sufficient suction, for example, the pressurewithin the evacuated volume could be less than approximately 50kilopascals. Further, the device 100 could be constructed such that theevacuated volume has a pressure less than some maximum value (e.g., 50kilopascals) for some specified minimum period of time such that theevacuated volume could be used as a suction source to draw blood from aformed puncture in skin into the device 100 and to the sensor 140 at aspecified future point in time. This could include high-quality sealsand adhesives between elements of the device 100 that comprise and/orform the evacuated volume. In some examples, surface elements (e.g., thehousing 110, the seal 143, the circuit board 115) of the device 100 thatare joined to form the evacuated volume could have highly smoothsurfaces. In some examples, the device 100 could be configured and/orassembled such that the pressure within the evacuated volume remainsbelow a specified maximum pressure for 48 hours, a week, or some otherspecified period of time to permit the use of the evacuated volume toprovide suction to draw blood into the device 100 at a specified futurepoint in time that is less than the specified period of time. In someexamples, this could include storing the device 100 in an evacuatedvolume of a package (e.g., within an evacuated and sealed blister ofpackaging material) and removing the device 100 from the evacuatedvolume of the package before mounting the device 100 to skin.

The seal 143 could be composed of a variety of materials to allowsuction to be applied to and contained by the seal 143 until the seal ispierced by the needle 120. Further, the seal 143 could be composed ofmaterials that are capable of being vacuum-formed into a specified shape(e.g., a shape that can be mounted to the housing 110 and that includesone or more concave depressions, e.g., 123). For example, the seal 143could be composed of polycarbonate.

The sensor 140 could be configured to detect a variety of properties ofblood drawn into the device 100 (e.g., 109). For example, the sensor 140could be configured to detect the presence, concentration, or otherproperties of an analyte (e.g., glucose, small molecules, cells, cellcounts, hormones, cholesterol, testosterone, thyroid hormones, vitamins,minerals, electrolytes, cortisol, creatinine, luteinizing hormone,follicle stimulating hormone) in the blood. In some examples, the sensor140 could be configured to detect a clotting rate, viscosity,osmolarity, or other property of the blood. The sensor 140 could beconfigured to detect the property of the blood through direct contactbetween the blood and one or more elements of the sensor 140. Forexample, the sensor 140 could be an electrochemical sensor configured toamperometrically, potentiometrically, or otherwise electrochemicallydetect one or more properties of the blood when the blood comes intocontact with one or more electrodes of the electrochemical sensor (e.g.,when the blood comes into contact with a working electrode of the sensor140 that is selectively sensitive to an analyte of interest in the bloodand further comes into contact with a reference electrode of the sensor140). In one example, the working electrode could comprise a chemicalthat is selectively sensitive to glucose (e.g., glucose oxidase), suchthat an electronic current is produced when glucose come into contactwith the working electrode. Additionally or alternatively, the sensor140 could be configured to detect a property of the blood when the bloodcomes into contact with an analyte-sensitive chemical (e.g., afluorophore, a chromophore) that has one or more optical properties(e.g., a color, a fluorescence intensity, a fluorescence lifetime) thatare related to the analyte in the blood, and the sensor 140 could detectthe analyte in the blood by optically interrogating (e.g., illuminatingand/or detecting light emitted from) the analyte-sensitive chemical.Additionally or alternatively, the sensor 140 could be configured todetect one or more properties of the blood without being in directcontact with the blood, e.g., by detecting a color of the blood, aproperty of motion of the blood, or some other property. The devicecould also comprise further sensors configured to detect some otherproperties of the device or the environment. In one example, the devicemay include an inertial measurement unit (e.g., an accelerometer) todetect a motion of the device (e.g., to ensure the user is stationarybefore the first blood measurements are taken).

Additionally or alternatively, a device as described herein could beconfigured to store blood emitted and/or drawn from skin (e.g., for somelater analysis). FIG. 3 shows a cross-sectional view of a device 300that is configured to be mounted to skin, to pierce the skin with aneedle 320, to retract the needle, and to draw blood from the skin intothe device 300 and to store the blood in a blood storage element 340.The needle 320 additionally acts to pierce a seal 343 such that suctionprovided by the device (e.g., by an evacuated volume 341 of the device)can be applied through a formed hole in the seal 343 to draw blood fromthe skin through the formed hole in the seal 343 and into the bloodstorage element 340. In the illustrated example, the blood storageelement 340 includes a capillary tube, but a blood storage element of adevice could additionally or alternatively include an ampoule, a basin,a pit, or some other geometry configured to contain blood. Further, ablood storage element (e.g., 340) could be configured to preserve,chemically modify, prevent clotting or coagulation of, or otherwisemanipulate the stored blood. For example, the blood storage element 340could contain heparin to prevent clotting and/or coagulation of drawn,stored blood. Alternatively, the blood storage element could beconfigured to allow the blood to dry, according to an application. Insome examples, the blood storage element could include an absorptivematerial, e.g., a piece of fabric configured to absorb blood or otherfluids.

Stored blood could be presented to a sensor or other element(s) of asensing device (e.g., a desktop or other device separate from ablood-accessing device as described herein, e.g., 100, 300) configuredto detect one or more properties of the stored blood. For example, ablood accessing device could be configured to be mounted to such asensing device and to provide the stored blood to the sensing device.This could include the sensing device detecting one or more propertiesof the stored blood while it remains in the blood-accessing device(e.g., by optically detecting a property of the stored blood byilluminating and/or receiving light from the stored blood through awindow, an optical fiber, or other optically transparent elements of theblood-accessing device). Additionally or alternatively, theblood-accessing device providing the stored blood to a sensing devicecould include the stored blood being removed from a blood storageelement or other components of the blood-accessing device.

A blood-accessing device or system as described herein (e.g., 100, 300)could include multiple sensors, blood-storage elements, needles,injectors, seals, and/or other elements. As illustrated in FIG. 1A,device 100 includes six sections, each section including a respectiveneedle, injector, suction source, and other elements. Each section isconfigured to drive its respective needle into skin, to subsequentlyretract the needle from the skin, and the receive blood emitted from theskin in response to being penetrated by the needle. Each section couldinclude one or more sensors, one or more blood storage elements, and/oradditional components configured to receive, transmit, measure, modify,or otherwise interact with blood received from the skin. The sections ofa device could be similarly configured (e.g., could include similarsensors, be configured to draw similar amounts of blood from skin in asimilar manner) or could be differently configured (e.g., differentsensors, differently configured injectors, differently configuredneedles).

The sections of a device could be operated to access blood from skin atrespective different points in time, e.g., at a number of points in timefollowing self-administration of a dose of a substance, in response toan input received by the user interface, in response to a commandreceived from a remote system in communication with the device (e.g.,wireless communication via Bluetooth, ZigBee, WiFi, or some otherwireless communications protocol), in response to a detected command(e.g., a button press) and/or behavior (e.g., in response to a detectionthat the wearer is stationary using, e.g., an inertial measurement unitof the device 100) of a wearer, based on a detected physiological stateof the wearer (e.g., a heart rate or blood pressure detected bysensor(s) of the device 100), or according to some other scheme. Thedevice could prompt the user via the user interface to perform someactions, and could access blood at one or more points in time relativeto such prompts. Additionally or alternatively, the device could receivea user input via the user interface, and could access blood at one ormore time points relative to the received user input. The device couldalso be operated in response to detecting that the device is mounted tothe body, detecting that the user is stationary, or in response to someother input.

In some examples, the user interface could be operated to prompt a userto self-administer a dose of a substance. Subsequently, a first sectionof the device could be operated (i.e., a first injector may be operatedto drive a first needle into skin to form a puncture in the skin suchthat a first amount of blood is received by a first sensor) such that afirst sensor can be operated to detect an amount of an analyte in afirst amount of blood. During one or more further subsequent periods oftime, one or more further sections of the device could be operated toreceive additional amounts of blood and to detect a concentration of theanalyte during the further subsequent periods of time. Additionally oralternatively, a section of the device could be operated to receive anamount of blood from the skin and to detect an amount of the analyteduring a period of time prior to prompting a user to perform some action(e.g., to take a baseline measurement of the analyte concentrationbefore the user has self-administered a dose of the substance). In someexamples, the user interface could be operated to provide information orinstructions to the user during the measurement period. For example, theuser interface could provide an indication of a previously detectedlevel of an analyte, provide an alert before or during activation of theinjector, instruct the user to remain stationary, or provide some otherinformation.

Additionally or alternatively, the device could operate to access bloodfrom the skin in response to receiving one or more user inputs. Forexample, the device could receive a user input via the user interface,e.g., an input indicating that the user has self-administered a dose ofa substance, information relating to the dose of the substance,information relating to the timing of subsequent activations,information relating to a health state of the user, or some other input.Responsive to receiving the user input, the device could operate toaccess an amount of blood from the wearer and to detect a glucose levelof the blood or to detect some other property of the blood using asensor. Additionally or alternatively, the device could be operated toaccess an amount of blood before receiving the user input (i.e., to takea baseline blood glucose measurement before ingestion of a glucosesolution) in response to a further user input, in response to detectingthe device is mounted to the body, in response to detecting the user isstationary (e.g., with an inertial measurement unit), or some otherinput. Further section(s), injectors, needles, sensors, or othercomponents could be operated at specified time points following receiptof the user input and/or further user inputs.

In another example, the device could receive a user input via the userinterface, e.g., an input indicating that the user is ready for a firstblood draw. Responsive to receiving the user input, the device couldoperate to access a first amount of blood and to detect a first amountof an analyte (e.g., take a baseline measurement of the analyte).Subsequent to accessing a first amount of blood, the device could promptthe user via the user interface to self-administer a dose of asubstance. Subsequent to prompting the user to self-administer the doseof a substance, the device could be operated to take a second and/orfurther blood sample(s) and measure additional amounts of an analyte.

One or more aspects of the device operations could be specified based ona user input. For example, the timing, frequency, number of activations,depth of penetration, volume of received blood, or another aspect of thedevice operations could be specified based on information input by auser. In one example, a patient, doctor, or nurse could input a desiredtesting scheme (e.g., a number of measurements, a testing duration) andthe device could operate sections of the device according to the inputtesting scheme. Additionally or alternatively, a testing scheme could beselected from a number of testing schemes stored in the device memory(e.g., different testing schemes corresponding to different diagnostictests, indications, users, or other options). In another example, thedevice could automatically determine a testing scheme based on someother information input by a user (e.g., information relating to thehealth state of a user, medical history, the analyte to be measured,time constraints, a desired accuracy or frequency of measurement, orsome other information). Aspects of the device operations could also bechanged, determined, or otherwise affected by user inputs during themeasurement period. For example, a patient, doctor, or nurse may providean input that causes the device to take additional measurements, delay aplanned measurement, change an aspect of the device operations, or stopthe device operations. In some embodiments, the device may be configuredto receive a user input from a remote system (e.g., a remote server, acomputing device, or a mobile phone).

A device as described herein could include more or fewer sections,organized similarly or differently (e.g., in a row, rather thancircularly as illustrated) than those embodiments illustrated herein. Inexamples wherein the injector and/or suction source are single-use(e.g., wherein the injector ignites a limited supply of a propellantand/or wherein suction is provided by a single evacuated volume) theblood-accessing device could be configured for a single use. In someexamples, such a single and/or limited-use (e.g., six uses, asillustrated in FIG. 1A) could be configured to be a removable and/orreplaceable element of some other device. For example, theblood-accessing device 100 could be configured to be removably mountedon or within a body-mountable device (e.g., a wrist-mountable device)that includes a controller, a user interface, a battery, acommunications interface, or some other elements. Such a body-mountabledevice could be configured to operate the limited-use blood-accessingdevice to access a number of samples of blood from skin (e.g., atrespective specified points in time). Once the body-mountable device hasoperated all of the limited-use sections of the blood-accessing device,the blood-accessing device could be removed from the body-mountabledevice and replaced. In some examples, the removed blood-accessingdevice could be configured to store blood, and blood stored in theremoved blood-accessing device could be presented to a sensing devicefor analysis (e.g., the removed blood-accessing device could be sent viapost to a sensing device at a laboratory that is remote from a user ofthe body-mountable device).

Note that the configurations and operations of devices as describedherein are meant as non-limiting examples of operation of devicesconfigured to puncture skin and to receive blood emitted from the skinin response to being punctured. Such devices could include a variety ofmeans for penetrating or piercing skin, for driving such penetratingmeans into skin, for subsequently retracting such penetrating means fromthe skin, for drawing, wicking, suctioning, or otherwise receiving bloodresponsively emitted from the skin, for storing the received blood, forsensing one or more properties of the received blood, for moving,directing, preserving, or otherwise interacting with the received blood,or for performing some additional or alternative operations of functionsaccording to an application.

III. EXAMPLE WEARABLE DEVICES

Wearable blood-accessing devices as described herein can be configuredto be mounted to an external body surface of a wearer and to enable avariety of applications and functions including accessing blood of thewearer (e.g., drawing, extracting, or otherwise receiving blood),storing such accessed blood, detecting one or more properties of suchaccessed blood, detecting some other properties of the body of thewearer (e.g., a pulse rate), or performing some other functions. Suchwearable devices could enable a variety of applications, includingmeasuring homological properties or other physiological informationabout a wearer, indicating such measured information or otherinformation to the wearer (e.g., using a vibrator, a screen, a beeper),recording such information, indicating such information to a remotesystem (e.g., a server in a physician's office), or other functions.

In some examples, a wearable device 400 is provided as a wrist-mounteddevice, as shown in FIGS. 4A and 4B. The wrist-mounted device 400 may bemounted to the wrist of a living subject with a wristband or cuff,similar to a watch or bracelet. The wearable device 400 can beconfigured to access blood of a wearer and to store, detect a propertyof, or otherwise interact with such accessed blood. The term “wearabledevice,” as used in this disclosure, refers to any device that iscapable of being worn at, on or in proximity to a body surface, such asa wrist, ankle, waist, chest, or other body part. In order to accessblood from within and/or beneath skin of the body, the wearable devicemay be positioned on a portion of the body where subsurface vasculatureor other targets or elements of the body of the wearer are easilyaccessed (e.g., punctured), the qualification of which will depend onthe type of system used. A mount 410, such as a belt, wristband, ankleband, etc. can be provided to mount the device at, on or in proximity tothe body surface. The mount 410 may prevent the wearable device frommoving relative to the body to allow for blood to be drawn from apuncture produced in the skin by the device 400 (e.g., by a driven andsubsequently retracted needle of the device) or according to some otherapplication or consideration. In one example, shown in FIGS. 4A and 4B,the mount 410 may take the form of a strap or band 420 that can be wornaround the wrist (or some other part) of the body. Further, the mount410 may include an adhesive layer for adhering the blood-accessingdevice 400 to the body of a wearer.

A housing 430 is disposed on the mount 410 such that it can bepositioned on the body. A contact surface 440 of the housing 430 isintended to be mounted facing to the external body surface. The housing430 may include sensors for detecting one or more physiologicalproperties of the wearer (e.g., a pulse, a blood oxygenation, a galvanicskin response). The contact surface 440 additionally includes a numberof concave depressions 450. Each concave depression 450 corresponds to ablood-accessing section of the device 400 that can be operated to drivea needle, through the concave depression (e.g., through a seal of thedevice and/or through a channel of the device configured to allow thepassage of the needle), into skin of a wearer and subsequently toretract the needle from the skin. Further, each section is configured toreceive blood responsively emitted from the skin (e.g., by wicking,capillary action, application of suction, or some other means) and tostore, detect a property of, or otherwise interact with the receivedblood.

The housing 430 could be configured to be water-resistant and/orwater-proof. That is, the housing 430 could be configured to includesealants, adhesives, gaskets, welds, transparent windows, apertures,press-fitted seams, and/or other joints such that the housing 430 isresistant to water entering an internal volume or volumes of the housing430 when the housing 430 is exposed to water. The housing 430 couldfurther be water-proof, i.e., resistant to water entering an internalvolume or volumes of the housing 430 when the housing 430 is submergedin water. For example, the housing 430 could be water-proof to a depthof 1 meter, i.e., configured to resist water entering an internal volumeor volumes of the housing 430 when the housing 430 is submerged to adepth of 1 meter.

The wearable device 400 may also include a user interface 490 via whichthe wearer of the device may receive one or more recommendations oralerts generated either from a remote server or other remote computingdevice, or from a processor within the device. For example, the userinterface 490 may be operated to alert the user to self-administer adose of a substance (e.g., a glucose solution) before taking a series ofmeasurements of an analyte in the blood. The alerts could be anyindication that can be noticed by the person wearing the wearable device400. For example, the alert could include a visual component (e.g.,textual or graphical information on a display), an auditory component(e.g., an alarm sound), and/or tactile component (e.g., a vibration).Further, the user interface 490 may include a display 492 where a visualindication of the alert or recommendation may be displayed. The display492 may further be configured to provide an indication of a measuredhemodynamic property of blood accessed from the body of the wearer usingthe device (e.g., to provide an indication of a blood glucose level ofthe wearer's blood). In one example, the device 400 determines a healthstate of the user based on the detected amounts of analyte in the firstand second amounts of blood and provides an indication of the determinedhealth state via the user interface 490 (e.g., uses temporal glucosemeasurements to provide an indication of a glucose clearance rate, adiagnosis of diabetes or prediabetes, etc).

Further, the user interface 490 may include one or more buttons 494 foraccepting inputs from the wearer. For example, the buttons 494 may beconfigured to change the text or other information visible on thedisplay 492. In some examples, the display 492 is a touchscreen display.The buttons 494 or display may be configured to accept inputs forcontrolling aspects of the data collection system, such as initiating ameasurement period (e.g., causing the device 400 to access blood of thewearer by driving a needle into skin or according to some other method),inputs indicating the wearer's current health state (i.e., normal,migraine, shortness of breath, heart attack, fever, “flu-like” symptoms,food poisoning, etc.), or inputs indicating the wearer's activities(e.g., self-administering a dose of a substance, the dosage of saidsubstance).

Note that example devices herein are configured to be mounted to a wristof a wearer. However, the embodiments described herein could be appliedto other body parts (e.g., an ankle, a thigh, a chest, an abdomen, aforehead, a thigh, a finger), or to detect hematological properties orother physiological properties in other environments. For example,embodiments described herein could be applied to detect one or moreproperties in a target environment (e.g., a natural environment, anenvironment of an industrial, pharmaceutical, or water treatmentprocess).

Blood-accessing sections of the device 400 could be single-use; forexample, an injector of one or more sections could ignite a limitedsupply of a propellant and/or wherein suction is provided for/in asection by a single evacuated volume. In such examples, such singleand/or limited-use blood-accessing sections could be configured to be aremovable and/or replaceable element of the wearable device 400. Forexample, FIGS. 5A and 5B show a blood-accessing device 500 that could beconfigured to be removably mounted on or within the wearable device 400.The blood-accessing device 500 includes a housing 510 that can bepositioned on skin of a body when the blood-accessing device 500 ismounted on or within the wearable device 400 and the wearable device 400is mounted to the body. A contact surface 505 of the housing 510 isintended to be mounted facing to the external body surface. The contactsurface 505 includes a number of concave depressions 520. Each concavedepression 520 corresponds to a blood-accessing section of theblood-accessing device 500 that can be operated (e.g., when mounted onor within the wearable device 400) to drive a needle, through theconcave depression (e.g., through a seal of the device and/or through achannel of the device configured to allow the passage of the needle),into skin of a wearer and subsequently to retract the needle from theskin. Further, each section is configured to receive blood responsivelyemitted from the skin (e.g., by wicking, capillary action, applicationof suction, or some other means) and to store, detect a property of, orotherwise interact with the received blood.

The wearable device 400 could be configured to operate theblood-accessing device 500 to access a number of samples of blood fromskin (e.g., at respective specified points in time over a measurementperiod). Once the body-mountable device has operated all of the sectionsof the blood-accessing device 500, the blood-accessing device 500 couldbe removed from the wearable device 400 and replaced. In some examples,this could include operating one or more injectors, suction sources,and/or other components of the blood-accessing device 500 (e.g., viaelectrical connector 540, optical receiver/transmitter 545, and/orelectronics 530). Additionally or alternatively, the wearable device 400could operate the blood-accessing device 500 using other means, e.g., byigniting propellant of the blood-accessing device 500 by heating thepropellant using a laser of the wearable device 400.

In some examples, the removed blood-accessing device 500 could beconfigured to store blood, and blood stored in the removedblood-accessing device 500 could be presented to a sensing device foranalysis (e.g., the removed blood-accessing device 500 could be sent viapost to a sensing device at a laboratory that is remote from a user ofthe body-mountable device 400). For example, samples of blood storedwithin the blood-accessing device 500 could be accessed via ports 550 ofthe blood-accessing device 500.

Additionally or alternatively, the wearable device 400 could beconfigured to detect one or more properties of the blood accessed usingthe blood-accessing device 500. In some examples, the blood-accessingdevice 500 could include one or more sensors configured to detect one ormore properties of blood. The wearable device 400 could operate thesensors of the blood-accessing device 500 (e.g., via electricalconnector 540, optical receiver/transmitter 545, and/or electronics 530.Additionally or alternatively, the wearable device 400 could beconfigured to illuminate and/or receive light emitted from theblood-accessing device 500 (e.g., to illuminate and/or receive lightemitted from an analyte-sensitive chemical that has one or more opticalproperties that is related to the analyte in the blood), via a window,optical fiber, or other optically transparent element(s) of theblood-accessing device 500) to detect one or more properties of theblood drawn, wicked, suctioned, or otherwise received from skin by theblood-accessing device 500.

Wearable blood-accessing devices and other embodiments as describedherein can include a variety of components configured in a variety ofways. Devices described herein could include electronics including avariety of different components configured in a variety of ways toenable applications of the wearable device. The electronics couldinclude controllers, amplifiers, switches, display drivers, touchsensors, inertial measurements units, wireless communications chipsets(e.g., Bluetooth radios or other radio transceivers and associatedbaseband circuitry to enable wireless communications between thewearable device and some other system(s)), or other components. Theelectronics could include a controller configured to operate one or moresensors, injectors, suction sources, and/or components of ablood-accessing device to detect one or more hematological or otherproperties of a body and/or to access and store or otherwise interactwith blood from within and/or beneath skin of the body. The controllercould include a processor configured to execute computer-readableinstructions (e.g., program instructions stored in data storage of thewearable device) to enable applications of the wearable device. Theelectronics can include additional or alternative components accordingto an application of the wearable device.

Wearable or otherwise-configured blood-accessing devices as describedherein could include one or more user interfaces. A user interface couldinclude a display (e.g., a touchscreen display) configured to present animage to a wearer and to detect one or more finger presses of a weareron the interface. The controller or some other component(s) of theelectronics could operate the user interface to provide information to awearer or other user of the device and to enable the wearer or otheruser to affect the operation of the wearable device, to determine someproperty of the wearable device and/or of the wearer of the wearabledevice (e.g., a hematological property of blood and/or a health state ofa wearer of the wearable device), or to provide some other functionalityor application to the wearer and/or user. As one example, the wearercould press an indicated region of the user interface to indicate thatthe wearable device should begin logging detected medical informationabout the wearer (e.g., to initiate one or more measurement periodsafter the user has self-administered a dose of a substance). In anotherembodiment, the user interface could prompt the user to self-administera dose of a substance. The user could then indicate via the userinterface that they have self-adminstered the dose of the substanceand/or or provide the user interface an indication of a dosage of theself-administered substance. Other indicated information, changes inoperation of the wearable device, or other functions and applications ofthe user interface are anticipated.

Note that the embodiments illustrated in the Figures are illustrativeexamples and not meant to be limiting. Alternative embodiments,including more or fewer components in alternative configurations areanticipated. A wearable, handheld, body-mountable, desktop, or otherwiseconfigured device could include multiple housings or other suchassemblies each containing some set of components to enable applicationsof such a device. A blood-accessing device as described herein could beconfigured to perform a variety of functions and to enable a variety ofapplications. Blood-accessing devices could be configured to operate inconcert with other devices or systems; for example, blood-accessingdevices could include a wireless communication interface configured totransmit data indicative of one or more properties of the blood of awearer of the wearable device. In one example, the device operationscould include transmitting, using the communication interface, anindication of the detected amounts of the analyte in the amounts ofblood received by the device over the measurement period. Otherembodiments, operations, configurations, and applications of ablood-accessing device as described herein are anticipated.

FIG. 6 is a block diagram of an example system including one or morewearable blood-accessing devices 600. The one or more wearable devices600 may be configured to transmit data via a communication interface 610over one or more communication networks 620 to a remote system 630, suchas a remote server, a computing device, or a mobile phone. In oneembodiment, the communication interface 610 includes a wirelesstransceiver for sending and receiving communications to and from theremote system 630. In further embodiments, the communication interface610 may include any means for the transfer of data, including both wiredand wireless communications. For example, the communication interfacemay include a universal serial bus (USB) interface or a secure digital(SD) card interface. Communication networks 620 may be any one of may beone of: a plain old telephone service (POTS) network, a cellularnetwork, a fiber network and a data network. The remote system 630 mayinclude any type of remote server, remote computing device or remotecloud computing network. In some examples, the communication network 620includes one or more intermediaries, for example, a mobile phone orother personal computing device, which in turn transmits the data to aserver or another remote system 630.

In addition to receiving communications from the wearable device 600,such as collected hematological properties or other collectedphysiological properties and data regarding health state as input by theuser and/or one or more properties of a wearer detected using a sensordisposed in the wearable device 600, the server may also be configuredto gather and/or receive either from the wearable device 600 or fromsome other source, information regarding a wearer's overall medicalhistory, environmental factors and geographical data. For example, auser account may be established on the server for every wearer thatcontains the wearer's medical history. Moreover, in some examples, theserver 630 may be configured to regularly receive information fromsources of environmental data, such as viral illness or food poisoningoutbreak data from the Centers for Disease Control (CDC) and weather,pollution and allergen data from the National Weather Service. Further,the server may be configured to receive data regarding a wearer's healthstate from a hospital or physician. Such information may be used in theserver's decision-making process, such as recognizing correlations andin generating clinical protocols.

Additionally, the server may be configured to gather and/or receive thedate, time of day and geographical location of each wearer of the deviceduring each measurement period. Such information may be used to detectand monitor spatial and temporal spreading of diseases. As such, thewearable device may be configured to determine and/or provide anindication of its own location. For example, a wearable device mayinclude a GPS system so that it can include GPS location information(e.g., GPS coordinates) in a communication to the server. As anotherexample, a wearable device may use a technique that involvestriangulation (e.g., between base stations in a cellular network) todetermine its location. Other location-determination techniques are alsopossible.

The server may also be configured to make determinations regarding thehealth state of a user based on the first and second measurements of theanalyte in the amount of blood received by the device. For example, theserver could be configured to compare data transmitted from the deviceto existing data input by the user (e.g., a baseline measurement of anamount of an analyte, information about the user's medical history, or ahealth state of the user). Data transmitted to the server (e.g., theamounts of the analyte in the amounts of blood received during themeasurement period) could also be compared to data from a largerpopulation, or compared to certain physiological parameter baselines tomake a determination about a health state of the user.

Further, some embodiments of the system may include privacy controlswhich may be automatically implemented or controlled by the wearer ofthe device. For example, where a wearer's collected hematologicalproperty data and health state data are uploaded to a cloud computingnetwork for trend analysis by a clinician, the data may be treated inone or more ways before it is stored or used, so that personallyidentifiable information is removed. For example, a user's identity maybe treated so that no personally identifiable information can bedetermined for the user, or a user's geographic location may begeneralized where location information is obtained (such as to a city,ZIP code, or state level), so that a particular location of a usercannot be determined.

Additionally or alternatively, wearers of a device may be provided withan opportunity to control whether or how the device collects informationabout the wearer (e.g., information about a user's medical history,social actions or activities, profession, a user's preferences, or auser's current location), or to control how such information may beused. Thus, the wearer may have control over how information iscollected about him or her and used by a clinician or physician or otheruser of the data. For example, a wearer may elect that data, such ashealth state and hematological properties, collected from his or herdevice may only be used for generating an individual baseline andrecommendations in response to collection and comparison of his or herown data and may not be used in generating a population baseline or foruse in population correlation studies.

IV. EXAMPLE ELECTRONICS

FIG. 7 is a simplified block diagram illustrating the components of adevice 700, according to an example embodiment. Device 700 may take theform of or be similar to one of the blood-accessing devices 100, 300,400, 500 shown in FIGS. 1A-B, 2A-D, 3, 4A-B, and 5A-B. However, device700 may also take other forms, such as an ankle, waist, or chest-mounteddevice. Device 700 could also take the form of a device that is notconfigured to be mounted to a body. For example, device 700 could takethe form of a handheld device configured to be maintained in proximityto skin by a user or operator of the device 700 or by a frame or othersupporting structure. Device 700 also could take other forms. Inparticular, FIG. 7 shows an example of a device 700 having first 710 andsecond 720 blood-accessing sections, a user interface 730, communicationinterface 735 for transmitting data to a remote system, and a controller740. The components of the device 700 may be disposed on a mount or onsome other structure for mounting the device to enable stable collectionof blood emitted from skin in response to penetration of the skin by oneor more needles of the device 700, for example, mounting to an externalbody surface where one or more portions of subsurface vasculature orother anatomical elements are readily accessible. Controller 740 may beprovided as a computing device that includes one or more processors 750.The one or more processors 750 can be configured to executecomputer-readable program instructions 770 that are stored in thecomputer readable data storage 760 and that are executable to providethe functionality of a device 700 described herein.

The computer readable medium 760 may include or take the form of one ormore non-transitory, computer-readable storage media that can be read oraccessed by at least one processor 750. The one or morecomputer-readable storage media can include volatile and/or non-volatilestorage components, such as optical, magnetic, organic or other memoryor disc storage, which can be integrated in whole or in part with atleast one of the one or more processors 750. In some embodiments, thecomputer readable medium 760 can be implemented using a single physicaldevice (e.g., one optical, magnetic, organic or other memory or discstorage unit), while in other embodiments, the computer readable medium760 can be implemented using two or more physical devices.

First 710 and second 720 blood-accessing sections could include anycomponents configured to drive a needle into skin, to subsequentlyretract the needle from the skin, to receive blood from the resultingpuncture in the skin (e.g., by applying suction to the skin), and toperform other functions as described elsewhere herein. Blood-accessingsections could include injectors, motors, piezoelectric transducers,solenoids, actuated valves, resistive heaters or otherpropellant-igniting components, or other components of an injectorconfigured to drive a needle into skin and/or to subsequently retractsuch a needle. Blood-accessing sections 710, 720 could includeblood-storage elements as described elsewhere herein to store blood for,e.g., later analysis. Blood-accessing sections 710, 720 could includesensors configured to detect an amount of an analyte in the blood drawn,wicked, suctioned, received, or otherwise accessed by theblood-accessing sections 710, 720. Blood-accessing sections 710, 720could include pumps or other elements (e.g., evacuated volumes)configured to provide suction (e.g., to draw skin toward and/or intoconcave depressions of the blood-accessing sections 710, 720, to drawblood from the skin into the device 700, to direct blood from within thedevice, 700, e.g., to one or more sensors, blood-storage elements, orother components of the device 700). The device 700 could includeadditional (or fewer) blood-accessing sections. The blood-accessingsections 710, 720 could be similarly or differently configured. Theblood-accessing sections 710, 720 could be part of a removable and/orreplaceable portion of the device 700. The device 700 may includefurther sensors (not shown), e.g., inertial measurements units (IMUs),heart rate sensors, galvanic skin response sensors, pulse oximeters, orother sensors configured to detect one or more properties of the body ofa wearer and/or of the environment of the device 700.

The program instructions 770 stored on the computer readable medium 760may include instructions to perform any of the methods described herein.For instance, in the illustrated embodiment, program instructions 770include a controller module 772, calculation and decision module 774 andan alert module 776.

Calculation and decision module 774 may include instructions foroperating the blood-accessing sections 710, 720 and analyzing datagenerated by the blood-accessing sections 710, 720 (e.g., by sensorsthereof) to determine one or more hematological properties of blood orother information (e.g., health states) of a body of a wearer of thedevice 700, such as a blood glucose level at a number of points in time.Calculation and decision module 774 can additionally includeinstructions for analyzing the data to determine if a medical conditionor other specified condition is indicated, or other analytical processesrelating to the environment proximate to the device 700 (e.g., based oninformation generated by additional sensors of the device 700). Inparticular, the calculation and decision module 774 may includeinstructions for operating the first 710 and second 720 blood-accessingsections to access blood (e.g., for operating resistive heating elementsof the blood-accessing sections 710, 720 to ignite propellant and driverespective needles into skin) at respective specified points in time(e.g., points in time after a user has self-administered a dose of asubstance). In one example, the calculation and decision module 774 maymake a determination about the health state of the user based on thedetected amounts of analyte in a first and second amount of bloodreceived by the first and second blood-accessing sections 710, 720(e.g., to determine whether a user is diabetic or prediabetic based on aseries of blood glucose measurements).

The controller module 772 can also include instructions for operating auser interface 730. For example, controller module 772 may includeinstructions for displaying data collected by the blood-accessingsections 710, 720 and analyzed by the calculation and decision module774, or for displaying one or more alerts generated by the alert module776. Controller module 772 may include instructions for displaying datarelated to a detected hematological property of accessed blood and/or adetermined health state of a wearer. In one example, the devicedetermines a health state of the user based on data collected by theblood-accessing sections 710, 720 and provides an indication of thedetermined health state via the user interface (e.g., uses temporalglucose measurements to provide an indication of a glucose clearancerate, a diagnosis of diabetes or prediabetes, etc).

Further, controller module 772 may include instructions to executecertain functions based on inputs accepted by the user interface 730,such as inputs accepted by a touchscreen or one or more buttons disposedon the user interface (e.g., to operate one or both of theblood-accessing sections 710, 720 to access blood from a wearer and/orto detect one or more properties of the accessed blood in response to aninput from the user). In one embodiment, the user may input via the userinterface an indication that they have self-adminstered the dose of thesubstance (i.e., to being taking a series of blood measurements via thefirst and second blood-accessing sections 710, 720).

Communication interface 735 may also be operated by instructions withinthe controller module 872, such as instructions for sending and/orreceiving information via a wireless antenna, which may be disposed onor in the device 700. The communication interface 735 can optionallyinclude one or more oscillators, mixers, frequency injectors, etc. tomodulate and/or demodulate information on a carrier frequency to betransmitted and/or received by the antenna. In some examples, the device700 is configured to indicate an output from the processor by modulatingan impedance of the antenna in a manner that is perceivable by a remoteserver or other remote computing device.

The program instructions of the calculation and decision module 874 may,in some examples, be stored in a computer-readable medium and executedby a processor located external to the device 700. For example, thedevice 700 could be configured to collect certain data regarding theamount on an analyte in blood from the user and then transmit the datato a remote system, which may include a server, a mobile device, apersonal computer, the cloud, or any other remote system, for furtherprocessing.

The computer readable medium 760 may further contain other data orinformation, such as medical and health history of a user of the device700, which may be useful in determining whether a medical condition orsome other specified condition is indicated. Further, the computerreadable medium 760 may contain data corresponding to certainphysiological parameter baselines, above or below which a medicalcondition is indicated. The baselines may be pre-stored on the computerreadable medium 760, may be transmitted from a remote source, such as aremote server, or may be generated by the calculation and decisionmodule 774 itself. The calculation and decision module 774 may includeinstructions for generating individual baselines for the user of thedevice 700 based on data collected based on a certain number of bloodsamples accessed using blood-accessing elements (e.g., 710, 720) of thedevice 700, or data input by the user via the user interface 730.Baselines may also be generated by a remote server and transmitted tothe device 700 via communication interface 735. The calculation anddecision module 774 may also, upon determining that a medical or otheremergency condition is indicated, generate one or more recommendationsfor the user of the device 700 based, at least in part, on consultationof a clinical protocol. Such recommendations may alternatively begenerated by the remote server and transmitted to the device 700.

In some examples, the collected hematological property data, baselineprofiles, health state information input by device users and generatedrecommendations and clinical protocols may additionally be input to acloud network and be made available for download by a user's physician.Trend and other analyses may also be performed on the collected data,such as hemodynamic property data and health state information, in thecloud computing network and be made available for download by physiciansor clinicians.

In response to a determination by the calculation and decision module774 that a medical or other specified condition is indicated (e.g., thata wearer is diabetic or prediabetic, based on a detected glucoseclearance rate calculated from the amount of glucose detected in theblood accessed from the body of the wearer during the measurementperiod), the alert module 776 may generate an alert via the userinterface 730. The alert may include a visual component, such as textualor graphical information displayed on a display, an auditory component(e.g., an alarm sound), and/or tactile component (e.g., a vibration).The textual information may include one or more recommendations, such asa recommendation that the user of the device contact a medicalprofessional, deliver a dose of a pharmaceutical (e.g., insulin), seekimmediate medical attention, or administer a medication.

V. EXAMPLE METHODS

FIG. 8 is a flowchart of a method 800 for operating a blood-accessingdevice, such as any of the devices shown in FIG. 1A-B, 2A-D, 3, 4A-B, or5A-B and described herein. For purposes of illustration, theblood-accessing device operated in method 800 includes: (i) a firstneedle, (ii) a first injector coupled to the first needle, (iii) a firstsensor, (iv) a second needle, (v) a second injector coupled to thesecond needle, (vi) a second sensor, and (vii) a user interface. Themethod 800 includes, during a first period of time, operating the userinterface to prompt a user of the device to self-administer a dose of asubstance (810). The user interface could be, for example, a visualdisplay or touchscreen which provides user-discernible indications(e.g., visual, audible, and/or tactile indications) during themeasurement period. For example, the user interface could providereadable instructions on a display which prompt the user toself-administer a dose of a substance. The dose of a substance could beany pharmaceutical agent, medication, food, reporter molecule, or othersubstance whose effects on the user could include causing one or morephysiological effects (e.g., a change in blood glucose level over time)that could be measured in the blood across one or more measurementperiods (e.g., a period after self-administration of a glucosesolution).

The method 800 also includes, during a second period of time that issubsequent to the first period of time, operating the first injector todrive the first needle into skin to form a puncture in the skin suchthat a first amount of blood is received by the first sensor of thedevice, wherein the first injector is coupled to the first needle (820).This could include operating the first injector at a specified point intime and/or in response to a command (e.g., a command received through auser interface of the device, a command generated by the device inresponse to detecting that skin is present proximate the device, acommand generated by a remote system in communication with theblood-accessing device, a command generated in response to sensing auser behavior). Operating the first injector could include igniting apropellant, e.g., by heating the propellant using a resistive heatingelement. Additionally or alternatively, operating the first injectorcould include operating a motor, solenoid, piezoelectric transducer, orother elements of the device and/or of the injector.

The method 800 could further include operating the first sensor todetect an amount of an analyte in a first amount of blood (830) (e.g.,to detect a glucose concentration in the blood). The sensor couldoperate based on contact between the amount of blood and one or moreelements of the sensor (e.g., an electrode of an electrochemicalsensor). Alternatively, such sensors could be non-contact sensors (e.g.,colorimetric or other optical sensors). Sensors could be configured todetect glucose, blood cell counts, electrolytes, hormones, cholesterol,or some other analytes in accessed blood.

The method 800 also includes, during a third period of time that issubsequent to the second period of time, operating the second injectorof the device to drive the second needle into the skin to form a furtherpuncture in the skin such that a second amount of blood is received bythe second sensor of the device, wherein the second injector is coupledto the second needle (840). This could include operating the secondinjector at a specified point in time and/or in response to a command(e.g., a command received through a user interface of the device, acommand generated by the device in response to detecting that skin ispresent proximate the device, a command generated by a remote system incommunication with the blood-accessing device, a command generated inresponse to sensing a user behavior). Operating the second injectorcould include igniting a propellant, e.g., by heating the propellantusing a resistive heating element. Additionally or alternatively,operating the second injector could include operating a motor, solenoid,piezoelectric transducer, or other elements of the device and/or of theinjector.

The method 800 also includes operating the second sensor to detect anamount of an analyte in the second amount of blood (850). The sensorcould operate based on contact between the amount of blood and one ormore elements of the sensor (e.g., an electrode of an electrochemicalsensor). Alternatively, such a sensor could be a non-contact sensor(e.g., a colorimetric or other optical sensor). Sensors could beconfigured to detect glucose, blood cell counts, electrolytes, hormones,cholesterol, or some other analytes in accessed blood.

FIG. 9 is a flowchart of a method 900 for operating a blood-accessingdevice, such as any of the devices shown in FIG. 1A-B, 2A-D, 3, 4A-B, or5A-B and described herein. For purposes of illustration, theblood-accessing device operated in method 900 includes: (i) a firstneedle, (ii) a first injector coupled to the first needle, (iii) a firstsensor, (iv) a second needle, (v) a second injector coupled to thesecond needle, (vi) a second sensor, (vii) a user interface. The method900 includes operating the first injector of the device to drive thefirst needle into skin to form a puncture in the skin such that a firstamount of blood is received by the first sensor of the device (910).This could include operating the first injector at a specified point intime and/or in response to a command (e.g., a command received throughthe user interface of the device, a command generated by the device inresponse to detecting that skin is present proximate the device, acommand generated by a remote system in communication with theblood-accessing device, a command generated in response to sensing auser behavior). Operating the first injector could include igniting apropellant, e.g., by heating the propellant using a resistive heatingelement. Additionally or alternatively, operating the first injectorcould include operating a motor, solenoid, piezoelectric transducer, orother elements of the device and/or of the injector.

The method 900 also includes operating the first sensor to detect anamount of an analyte in the first amount of blood (920). The sensorcould operate based on contact between the amount of blood and one ormore elements of the sensor (e.g., an electrode of an electrochemicalsensor). Alternatively, such a sensor could be a non-contact sensor(e.g., colorimetric or other optical sensor). Sensors could beconfigured to detect glucose, blood cell counts, electrolytes, hormones,cholesterol, or some other analytes in accessed blood.

The method 900 also includes receiving a user input via the userinterface of the device (930). The user interface could include atouchscreen display or one or more buttons for accepting inputs from thewearer. The user interface may be configured to accept inputs forcontrolling aspects of the data collection system, such as initiating ameasurement period (e.g., causing the device to access blood of thewearer by driving a needle into skin or according to some other method),inputs indicating the wearer's current health state (i.e., normal,migraine, shortness of breath, heart attack, fever, “flu-like” symptoms,food poisoning, etc.), or inputs indicating the wearer's activities(e.g., self-administering a dose of a substance, the dosage of saidsubstance). In one example, the user could input via the user interfacean indication that they have self-administered a dose of a substance(e.g., a glucose solution), which could initiate a measurement period ofthe device.

The method 900 also includes, responsive to the user input, during asecond period of time that is subsequent to the first period of time,operating the second injector of the device to drive the second needleinto the skin to form a further puncture in the skin such that a secondamount of blood is received by the second sensor of the device, whereinthe second injector is coupled to the second needle (940). This couldinclude operating the second injector at a specified point in timeand/or in response to a command (e.g., a command received through a userinterface of the device, a command generated by the device in responseto detecting that skin is present proximate the device, a commandgenerated by a remote system in communication with the blood-accessingdevice, a command generated in response to sensing a user behavior).Operating the second injector could include igniting a propellant, e.g.,by heating the propellant using a resistive heating element.Additionally or alternatively, operating the second injector couldinclude operating a motor, solenoid, piezoelectric transducer, or otherelements of the device and/or of the injector.

The method 900 also includes operating the second sensor to detect anamount of an analyte in the second amount of blood (950). The sensorcould operate based on contact between the amount of blood and one ormore elements of the sensor (e.g., an electrode of an electrochemicalsensor). Alternatively, such a sensor could be a non-contact sensor(e.g., a colorimetric or other optical sensor). Sensors could beconfigured to detect glucose, blood cell counts, electrolytes, hormones,cholesterol, or some other analytes in accessed blood.

The methods 800, 900 could include additional or alternative steps. Forexample, the methods 800, 900 could include operating a third injectorof the device to drive a third needle into the skin to form a puncturein the skin such that a third amount of blood is received by a thirdsensor of the device, and operating the third sensor to detect an amountof the analyte in the third amount of blood prior to the operation ofthe first and second injectors (i.e., to take a baseline measurementbefore self-administration of a dose of a substance). The methods 800,900 could include heating, applying suction to, or otherwise preparing aportion of skin to emit blood in response to being pierced by a needleof the system. In some examples, the system could include one or moreblood storage elements configured to receive and store blood accessed bythe system and the methods 800, 900 could include storing the accessedblood. The methods 800, 900 could further include providing blood storedby the blood storage element to a sensing device and operating thesensing device to detect a property of the blood provided to the sensingdevice. In some examples, one or more elements, sections, or portions ofthe system (e.g., a section configured to drive a needle into skin,subsequently retract the needle, and to apply suction to the skin todraw blood into the section) could be removable, and the methods 800,900 could include removing and replacing such elements, sections, orportions subsequent to operating such elements, sections, or portions toaccess blood from skin.

The methods 800, 900 could include transmitting via a communicationinterface (e.g., wirelessly transmitting, transmitting via a Bluetoothwireless link, transmitting via a cable, transmitting via the internetor some other network) information indicative of a detected amount of ananalyte in blood accessed by the device or some other physiologicalproperty detected and/or determined by the device. In some examples, themethods 800, 900 could include determining a health state of the wearerbased on the amounts of an analyte detected from blood accessed by thedevice. In some examples, the methods 800, 900 could include indicatinga detected hematological properties, amounts of an analyte, or adetermined health state to a user via a user interface of the deviceand/or indicating such information to a remote system (e.g., to aphysician's computer, via a wireless or other communications link).

The example methods 800, 900 illustrated in FIGS. 8 and 9 are meant asillustrative, non-limiting examples. Additional or alternative elementsof the methods and additional or alternative components of the systemsare anticipated, as will be obvious to one skilled in the art.

VI. CONCLUSION

Where example embodiments involve information related to a person or adevice of a person, the embodiments should be understood to includeprivacy controls. Such privacy controls include, at least, anonymizationof device identifiers, transparency and user controls, includingfunctionality that would enable users to modify or delete informationrelating to the user's use of a product.

Further, in situations in where embodiments discussed herein collectpersonal information about users, or may make use of personalinformation, the users may be provided with an opportunity to controlwhether programs or features collect user information (e.g., informationabout a user's medical history, social network, social actions oractivities, profession, a user's preferences, or a user's currentlocation), or to control whether and/or how to receive content from thecontent server that may be more relevant to the user. In addition,certain data may be treated in one or more ways before it is stored orused, so that personally identifiable information is removed. Forexample, a user's identity may be treated so that no personallyidentifiable information can be determined for the user, or a user'sgeographic location may be generalized where location information isobtained (such as to a city, ZIP code, or state level), so that aparticular location of a user cannot be determined. Thus, the user mayhave control over how information is collected about the user and usedby a content server.

The particular arrangements shown in the Figures should not be viewed aslimiting. It should be understood that other embodiments may includemore or less of each element shown in a given Figure. Further, some ofthe illustrated elements may be combined or omitted. Yet further, anexemplary embodiment may include elements that are not illustrated inthe Figures.

Additionally, while various aspects and embodiments have been disclosedherein, other aspects and embodiments will be apparent to those skilledin the art. The various aspects and embodiments disclosed herein are forpurposes of illustration and are not intended to be limiting, with thetrue scope and spirit being indicated by the following claims. Otherembodiments may be utilized, and other changes may be made, withoutdeparting from the spirit or scope of the subject matter presentedherein. It will be readily understood that the aspects of the presentdisclosure, as generally described herein, and illustrated in thefigures, can be arranged, substituted, combined, separated, and designedin a wide variety of different configurations, all of which arecontemplated herein.

What is claimed is:
 1. A system comprising: a first needle; a firstinjector, wherein the first injector is coupled to the first needle; afirst sensor; a second needle; a second injector, wherein the secondinjector is coupled to the second needle; a second sensor; a userinterface; and a controller, wherein the controller is programmed toperform operations comprising: during a first period of time, operatingthe user interface to prompt a user to self-administer a dose of asubstance; during a second period of time that is subsequent to thefirst period of time by a first delay period relative to the firstperiod of time, operating the first injector to drive the first needleinto skin to form a puncture in the skin such that a first amount ofblood is received by the first sensor; operating the first sensor todetect an amount of an analyte in the first amount of blood; during athird period of time that is subsequent to the second period of time andthat is subsequent to the first period of time by a second delay periodrelative to the first period of time, operating the second injector todrive the second needle into the skin to form a further puncture in theskin such that a second amount of blood is received by the secondsensor; and operating the second sensor to detect an amount of theanalyte in the second amount of blood.
 2. The system of claim 1, whereinthe first injector comprises: a chamber, wherein the first needle isdisposed at least partially within the chamber, a piston disposed in thechamber, wherein the first needle is coupled to the piston, and whereinthe piston is configured to slidably move within the chamber, and apropellant, wherein the propellant is configured to slidably move thepiston within the chamber to drive the first needle into skin; whereinoperating the first injector to drive the first needle into the skincomprises igniting the propellant.
 3. The system of claim 1, furthercomprising: a third needle; a third injector, wherein the third injectoris coupled to the third needle; and a third sensor; wherein theoperations further comprise: prior to the first period of time,operating the third injector to drive the third needle into the skin toform a further puncture in the skin such that a third amount of blood isreceived by the third sensor; and operating the third sensor to detectan amount of the analyte in the third amount of blood.
 4. The system ofclaim 1, further comprising a suction source configured to providesuction, wherein the suction provided by the suction source isconfigured to draw blood from the formed puncture in the skin to thefirst sensor.
 5. The system of claim 1, further comprising: a seal; anda suction source; wherein the seal is configured to receive suctionprovided by the suction source, wherein the first injector driving thefirst needle into the skin comprises driving the first needle throughthe seal to form at least one hole in the seal, and wherein the suctionprovided by the suction source is configured to draw blood from theformed puncture in the skin through the formed at least one hole in theseal to the first sensor.
 6. The system of claim 1, wherein theoperations further comprise: determining a health state based on thedetected amounts of the analyte in the first and second amounts ofblood; and providing an indication of the determined health state viathe user interface.
 7. The system of claim 1, wherein the user interfacecomprises a display.
 8. The system of claim 1, further comprising aninertial measurement unit, wherein the operations further compriseoperating the inertial measurement unit to detect a motion of thesystem.
 9. The system of claim 1, further comprising a communicationinterface, wherein the operations further comprise transmitting, usingthe communication interface, an indication of the detected amounts ofthe analyte in the first and second amounts of blood to a remote system.10. The system of claim 1, further comprising a mount, wherein the mountis configured to secure the system to an external body surface.
 11. Thesystem of claim 10, wherein the mount comprises an adhesive layer. 12.The system of claim 1, wherein the detected analyte is glucose.
 13. Asystem comprising: a first needle; a first injector, wherein the firstinjector is coupled to the first needle; a first sensor; a secondneedle; a second injector, wherein the first injector is coupled to thefirst needle; a second sensor; a user interface; and a controller,wherein the controller is programmed to perform operations comprising:during a first period of time, operating the first injector to drive thefirst needle into skin to form a puncture in the skin such that a firstamount of blood is received by the first sensor; operating the firstsensor to detect an amount of an analyte in the first amount of bloodreceiving a user input via the user interface; responsive to receivingthe user input, during a second period of time that is subsequent to thefirst period of time and that is subsequent to receiving the user inputby a first delay period, operating the second injector to drive thesecond needle into the skin to form a further puncture in the skin suchthat a second amount of blood is received by the second sensor; andoperating the second sensor to detect an amount of the analyte in thesecond amount of blood.
 14. The system of claim 13, wherein the firstinjector comprises: a chamber, wherein the first needle is disposed atleast partially within the chamber, a piston disposed in the chamber,wherein the first needle is coupled to the piston, and wherein thepiston is configured to slidably move within the chamber, and apropellant, wherein the propellant is configured to slidably move thepiston within the chamber to drive the first needle into skin, whereinoperating the first injector to drive the first needle into the skincomprises igniting the propellant.
 15. The system of claim 13, furthercomprising: a third needle; a third injector, wherein the third injectoris coupled to the third needle; and a third sensor; wherein theoperations further comprise: during a third period of time that issubsequent to the second period of time and that is subsequent to thetiming of receiving the user input by a second delay period, operatingthe third injector to drive the third needle into the skin to form afurther puncture in the skin such that a third amount of blood isreceived by the third sensor; and operating the third sensor to detectan amount of the analyte in the third amount of blood.
 16. The system ofclaim 13, further comprising: a third needle; a third injector, whereinthe third injector is coupled to the third needle; and a third sensor;wherein the user input comprises an indication of an interval duration,and wherein the operations further comprise: operating the thirdinjector to drive the third needle into the skin to form a furtherpuncture in the skin such that a third amount of blood is received bythe third sensor, wherein the third injector is operated to drive thethird needle into the skin subsequent to the second injector beingoperated to drive the second needle into the skin by a period of timecorresponding to the indicated interval duration.
 17. The system ofclaim 13, further comprising a suction source configured to providesuction, wherein the suction provided by the suction source isconfigured to draw blood from the formed puncture in the skin to thefirst sensor.
 18. The system of claim 13, wherein the user inputcomprises an indication of a dosage of a self-administered substance.19. The system of claim 13, wherein the operations further comprise:responsive to detecting the amount of the analyte in the first amount ofblood, operating the user interface to provide an indication of thedetected amount of the analyte in the first amount of blood.
 20. Thesystem of claim 13, wherein the operations further comprise: determininga health state based on the detected amounts of the analyte in the firstand second amounts of blood; and providing an indication of thedetermined health state via the user interface.
 21. The system of claim13, wherein the user interface comprises a touch screen.
 22. The systemof claim 13, further comprising an inertial measurement unit, whereinthe operations further comprise operating the inertial measurement unitto detect a motion of the system.
 23. The system of claim 13, furthercomprising a communication interface, wherein the operations furthercomprise transmitting, using the communication interface, an indicationof the detected amounts of the analyte in the first and second amountsof blood to a remote system.
 24. The system of claim 13, furthercomprising a mount, wherein the mount is configured to secure the systemto an external body surface.
 25. The system of claim 24, wherein themount comprises an adhesive layer.
 26. The system of claim 13, whereinthe detected analyte is glucose.
 27. A method comprising: during a firstperiod of time, operating a user interface of a device to prompt a userto self-administer a dose of a substance; during a second period of timethat is subsequent to the first period of time by a first delay periodrelative to the first period of time, operating a first injector of thedevice to drive a first needle into skin to form a puncture in the skinsuch that a first amount of blood is received by a first sensor of thedevice, wherein the first injector is coupled to the first needle;operating the first sensor to detect an amount of an analyte in thefirst amount of blood; during a third period of time that is subsequentto the second period of time and that is subsequent to the first periodof time by a second delay period relative to the first period of time,operating a second injector of the device to drive a second needle intothe skin to form a further puncture in the skin such that a secondamount of blood is received by a second sensor of the device, whereinthe second injector is coupled to the second needle; and operating thesecond sensor to detect an amount of the analyte in the second amount ofblood.
 28. The method of claim 27, wherein the first injector comprises:a chamber, wherein the first needle is disposed at least partiallywithin the chamber, a piston disposed in the chamber, wherein the firstneedle is coupled to the piston, and wherein the piston is configured toslidably move within the chamber, and a propellant, wherein thepropellant is configured to slidably move the piston within the chamberto drive the first needle into skin; wherein operating the firstinjector to drive the first needle into the skin comprises igniting thepropellant.
 29. The method of claim 27, further comprising: prior to thefirst period of time, operating a third injector of the device to drivea third needle into the skin to form a further puncture in the skin suchthat a third amount of blood is received by a third sensor of thedevice, wherein the third injector is coupled to the third needle; andoperating the third sensor to detect an amount of the analyte in thethird amount of blood.
 30. The method of claim 29, further comprising:determining a health state based on the detected amount of the analytein the third amount of blood; and providing an indication of thedetermined health state via the user interface.
 31. The method of claim27, further comprising: operating a suction source of the device toprovide suction, wherein the suction provided by the suction source isconfigured to draw blood from the formed puncture in the skin to thefirst sensor.
 32. The method of claim 27, wherein the operations furthercomprise: determining a health state based on the detected amounts ofthe analyte in the first and second amounts of blood; and providing anindication of the determined health state via the user interface. 33.The method of claim 27, wherein the user interface comprises a display.34. The method of claim 27, further comprising: transmitting, using acommunication interface of the device, an indication of the detectedamounts of the analyte in the first and second amounts of blood to aremote system.
 35. The method of claim 27, wherein the detected analyteis glucose.
 36. A method comprising: during a first period of time,operating a first injector of a device to drive a first needle into skinto form a puncture in the skin such that a first amount of blood isreceived by a first sensor of the device, wherein the first injector iscoupled to the first needle; operating the first sensor to detect anamount of an analyte in the first amount of blood; receiving a userinput via a user interface of the device; responsive to receiving theuser input, during a second period of time that is subsequent to thefirst period of time and that is subsequent to receiving the user inputby a first delay period, operating a second injector of the device todrive a second needle into the skin to form a further puncture in theskin such that a second amount of blood is received by a second sensorof the device, wherein the second injector is coupled to the secondneedle; and operating the second sensor to detect an amount of theanalyte in the second amount of blood.
 37. The method of claim 36,wherein the first injector comprises: a chamber, wherein the firstneedle is disposed at least partially within the chamber, a pistondisposed in the chamber, wherein the first needle is coupled to thepiston, and wherein the piston is configured to slidably move within thechamber, and a propellant, wherein the propellant is configured toslidably move the piston within the chamber to drive the first needleinto skin, wherein operating the first injector to drive the firstneedle into the skin comprises igniting the propellant.
 38. The methodof claim 36, further comprising: during a third period of time that issubsequent to the second period of time and that is subsequent to thetiming of receiving the user input by a second delay period, operating athird injector of the device to drive a third needle into the skin toform a further puncture in the skin such that a third amount of blood isreceived by a third sensor of the device, wherein the third injector iscoupled to the third needle; and operating the third sensor to detect anamount of the analyte in the third amount of blood.
 39. The method ofclaim 38, wherein the user input comprises an indication of an intervalduration, and further comprising: operating the third injector to drivethe third needle into the skin to form a further puncture in the skinsuch that a third amount of blood is received by the third sensor,wherein the third injector is operated to drive the third needle intothe skin subsequent to the second injector being operated to drive thesecond needle into the skin by a period of time corresponding to theindicated interval duration.
 40. The method of claim 36, furthercomprising: operating a suction source of the device to provide suction,wherein the suction provided by the suction source is configured to drawblood from the formed puncture in the skin to the first sensor.
 41. Themethod of claim 36, wherein the user input comprises an indication of adosage of a self-administered substance.
 42. The method of claim 36,further comprising: responsive to detecting the amount of the analyte inthe first amount of blood, operating the user interface to provide anindication of the detected amount of the analyte in the first amount ofblood.
 43. The method of claim 36, further comprising: determining ahealth state based on the detected amounts of the analyte in the firstand second amounts of blood; and providing an indication of thedetermined health state via the user interface.
 44. The method of claim36, wherein the user interface comprises a touch screen.
 45. The methodof claim 36, further comprising: transmitting, using a communicationinterface of the device, an indication of the detected amounts of theanalyte in the first and second amounts of blood to a remote system. 46.The method of claim 36, wherein the detected analyte is glucose.